Sempu wanted

[FETguy]

My Sempu is toast, and I'd like to replace it with same if I can find one. It is the T2 model, for 68mm bottom bracket, width = 115 mm, 1.37" - 24 thread. Anybody got one kicking around? Thanks!

 

[The Toecutter]

My Sempu is toast, and I'd like to replace it with same if I can find one. It is the T2 model, for 68mm bottom bracket, width = 115 mm, 1.37" - 24 thread. Anybody got one kicking around? Thanks!

I have some, but they aren't for sale as they are for my current projects and as spares. I was able to procure them from the link below:

https://www.aliexpress.us/item/2251...list.product.mainProduct&gatewayAdapt=glo2usa

 

[FETguy]

Thanks! I've got one on order now. I'm glad that they are still available. This type of sensor seems like an endangered species, so if it works like the original one, I'll buy a spare.

 

[The Toecutter]

Thanks! I've got one on order now. I'm glad that they are still available. This type of sensor seems like an endangered species, so if it works like the original one, I'll buy a spare.

Be careful when assembling the 5-pin JST connector to have all reference diagrams handy for both the Sempu and the Cycle Analyst or whatever other computer you are using.

 

[Chalo]

My Sempu is toast,

Yeah, that's why I gave up on DIY torque sensors. But feel free to keep trying.

 

[FETguy]

Yeah, that's why I gave up on DIY torque sensors. But feel free to keep trying.

My fault. I foolishly coasted down our hill with my battery disconnect open. When I engaged regen braking (which I love!), the voltage went through the roof. The controller survived but the Sempu did not. I'll avoid that maneuver in the future, but will also add a resistor and TVS to the supply line to the torque sensor. Otherwise the Sempu has been great.

What do you think of the Fischer sensors at Grin? I may migrate to that and buy a spare.

Seems clear that these old school bottom bracket sensors are an endangered species. Not many people running this setup.

 

[FETguy]

Be careful when assembling the 5-pin JST connector to have all reference diagrams handy for both the Sempu and the Cycle Analyst or whatever other computer you are using.

No problem there. I'm the one who pointed out that the Sempu may overload the 10V supply from a CA and should instead be powered from a higher voltage, like full battery if that is within the 60V rating. The failure was "operator error".